The yellowing is normal in the larger fan and sun leafs late in flower. What is happening is the bud that is closest to the leaf is using up the energy of that leaf and does not need that leaf anymore.

Once it turns over 50% yellow then it no-longer produces chlorophyll so you can cut it. Just when you do cut it leave a small bit of the stem from the leaf still attached to the stock. That way there is no damage to the stock and the plant will heal better and be stronger for that.

Now for the disclosure: Not all of yellowing is from that and some is signs of nutrient problems so it's up to you to check the Ph, TDS, and other little signs of multiple problems.

Those are the little nuance that I keep talking about but it does take years to know them by sight so you can correct problems before they get out of hand or if it's just nature being nature.
Zandor Reviewed by Zandor on . Question on a Nitrogen Deficiency? Hello Everyone, Noticed some yellowing on my leaves, mostly towards the bottom 1/3 of the plant, but also some yellowing on the top 1/3 of the plant as well. Bought some nitrogen heavy nutes to give them, and I have given water two times with the added nutrients (first time was five days ago) Tonight was the first water without the nitrogen added. About two days ago things started to appear much greener, with little sight of yellowing leaves. I take off the ones that become Rating: 5